Disgracing the name of the company publicly certainly does affect the reputution. It's not a good practise to go on for complains or abuse for small small issues as it's a normal thing for a big company and it does happens with us too.
Humans wants are unlimited.
Be the Hero of the zero hour!
Sometimes companies do not responded after many reminders and do not attend calls of costumers and costumers are forced to make negative remarks of the companies.
I have also done these types of negative remarks for 3-4 companies which did not responded me after many emails.
Honesty is the best policy.